Feasibility of filtering gray water for drinking again, using a gravity-fed filter system?

[Frood]

Simple science says that distillation removes almost anything from the water, and boiling the water (which happens during the distillation process) kills any organisms in the water.

The only thing left are certain chemicals like benzine which will evaporate and condense before the water does, because of the lower boiling point. These chemicals can be removed by not condensing the water until it reaches the boiling point. The chemicals will boil out first.

Unless you are downstream from a location where solvents are used, your fine! And if you're in the woods, it's pretty much a sure thing that there's no

I'd be happy to try it.

This is why you throw away the heads... The volatiles that turn vaporous at a lower temperature than water. You also don't want to distill 100% of your solution either... you want to leave the things that are harder to convert to gaseous form than water so need a higher temperature.

Basically if you know your liquid solution is 90% water, then if you have 10 ounces of solution you will discard the first ounce and make sure that you leave at least one ounce at the end... otherwise you are just leaving behind the solids that won't turn gaseous but any other chemical contaminants that were in your water get condensed back into liquid form during the distillation process.

Please keep in mind this is massively oversimplifying distillation. To do it efficiently you should know the vaporization temperature of your target distillate and keep the temperature of the solution right... aannnd I could write a lot more about this but will just stop now. You would likely be better off buying a book about distillation and home brewing

 

[dreamrunnerjt]

I am toying around with the same idea, recycle grey water but only shower water, not the sink. I plan on making a tall vertical sieve with 6' x 3" PVC pipe packed with swimming pool sand and several layers of activated charcoal with filter media on bottom to keep the sand out of the exit slats. It will sit in a 5-gallon bucket with a modified lid (dust free) and have a 2 gallon top (with strainer) for pouring 1 gallon of shower water in at a time and let it take its course. Lid on top (dust free). Will probably wipe off a little before the shower, yes, no #1 in the shower pan. Maybe change out sand and activated carbon when I smell an odor. Thoughts , soap type, issues, yes, no, not no, but hell no, ??

There are several commercially available water filters that contain those items and are not very expensive.

 

[dreamrunnerjt]

I had been wondering of anyone used a dehumidifier to reduce the moisture in their rigs. So many post warning against moisture build up and mold. I have not tested water from a dehumidifier but I would think it would be cleaner than river or rain water. If you are getting a couple of gallons a day it could surely be used for dishes and other household cleaning. I think you would be able to run it through a filter like brita and boil it and/or even use a uv light and it would be okay to drink. Has anyone tried it? Or at least have the ability to test such a thing?

 

[bullfrog]

A dehumidifier takes a lot of power I believe and keeping the coils clean might prove difficult.

 

[Solarcoast]

I was looking into making a recirculating shower, but after looking at what others have done there were several issues.

Even with 7 levels of filtration the water gets progressively more nasty every time you use it. I would never drink it after one use let alone multiple ones.

If you use soap, even the natural kind, it very quickly clogs the filters, and some of it still gets through to the "clean" water.

That's not taking into account washing dishes as well, that just adds a whole additional level of crud for the filters to deal with.

It's a good idea but technology doesn't seem to be there yet.

 

[LargeMarge]

Greetings.

Since most of us...

• Would that water be safe to drink...

.
a)
Water is cheap.
RO water from a dispenser machine at the grocery store is our preference.
Allegedly, this water contains zero meds and zero plastics, common pollutants.
.
Storing water is simple.
Glass jugs, stainless steel retired Pepsi kegs such as we use, plastic jugs (please, no lewd comments about cosmetic surgery!).
.
Disposal of used water is straightforward.
Depending on type, a nearby bush or gopher-hole, or haul it to a treatment plant.
.
Many full-time live-aboard boats use an on-board RO 'system' for unlimited fresh water.
Unfortunately, that equipment furnishes approximately a 20% (twenty percent) product per intake, with about 80% (eighty percent) returned to source.
.
With all the quick easy sources of fresh clean drinking water, would I trust a complicated technology to process 'gray' sewage?
I think the effort exceeds the reward.
.
b)
I think your 'most of us' claim is flawed.
.
I think each individual camper quickly establishes an individual standard for use and disposal of any resource:
* 'I am comfortable carrying x-amount of trash before I need a Dumpster®'
* 'I need x-amount of back-up food to feel comfortable'
* 'I require x-amount of space between me and those nincompoops!'
.
I think 'most of us', eventually inevitably, are in the simplification business.
In my case, I have a strong need to avoid technology requiring my undivided attention... but if my attention lags for just one instant, could turn my guts to mush...
... but you go right ahead.

 

[Solarcoast]

One suggestion if you do try something like this is to still keep drinking water and the recirculated water systems completely separate.

If you drink the water it is being consumed and removed from the system either way, you aren't saving any water by drinking gray water.

You'll need to add fresh water to replace all that you drink, so there is no point in fouling the water and then drinking it as opposed to just drinking it fresh.

 

[user 423]

^The grey water is normally disposed of.

So if you were able to filter it successfully and use it as drinking water, you would then need to store less drinking water.

How is that not saving water? (not that I would want to try it)

 

[Solarcoast]

^The grey water is normally disposed of.

So if you were able to filter it successfully and use it as drinking water, you would then need to store less drinking water.

How is that not saving water? (not that I would want to try it)

Reusing gray water for washing/showering will save water. Drinking it won't because that water is being removed from the system.

Say you start with 25gal of water and use it for drinking and washing all in one system. Say you drink 1 gal per day and keep the last five gallons in the system.

After 20 days you'll have consumed 20 gal of water and have 5 gallons left in the system for washing, so you'll be out of drinking water

Now if instead of drinking gray water you drink fresh water. You drink the same 1gal per day. You start with the same 25gal but you keep 20g fresh and keep 5g in a recirculating system. After 20 days you'll have no drinking water left just like before, and you'll have 5gal in the recirculating system for washing just like before

Your water usage over time is the same, you are losing/using 1gal a day. The only advantage comes from reusing gray water for washing, showering etc as you are putting that water back into the system after use. When drinking it you are not.

 

[LargeMarge]

^The grey water is normally disposed of.

So if you were able to filter it successfully and use it as drinking water, you would then need to store less drinking water.

How is that not saving water? (not that I would want to try it)

.
a)
Assumes a 'zero-loss' closed system.
.
b)
While parked, our south-facing cab is a green-house for herbs and sprouts.
We are automatically in it several times daily for pickin's and to verify ('double-check, then triple-check') soil moisture in our midget planters.
.
If I could seal the cab, then harvest the humidity, that could reduce the water required by our on-board garden.
However, how much water would leave that enclosed system each time some sprouts are harvested, the living things composed of water plus green stuff?
.
I grew-up on a farm in the mountains east of Sacramento, California.
As we did chores around the acreage, I frequently emptied my bladder behind some handy tree.
On cold mornings, I remember thinking of some way to re-cycle the heat lost by the 98.6°f water leaving my chilly bones.
.
Not the whiz, just the heat...

 

[maki2]

You can distill it using solar energy. There are 3rd world places in desert areas where projects have been setup to do such things. Not sure if it is being used as drinking water for human consumption or just for livestock and chores such as laundry.

I have seen an RV endless hot water shower project on YouTube where the shower water is filtered for reuse as shower water.

 

[dreamrunnerjt]

I have considered almost all of the options suggested here. Running my gray water through a sand, charcoal, fiber filter but mostly to water plants I hope to carry. Using a dehumidifier to refill/add to "fresh" water. I would probably be adding a few drops of bleach to that. And using a tarp to collect rain water to add to fresh. I hope to do some sort of prefiltering before adding that to my fresh tank and again a few drops of bleach. Regardless of what I put in my fresh tank I will be filtering all drinking water with a Berkly or something like it. May even add a UV light to my fresh tank as I hear it helps with killing things I don't want there. One of my many dreams. Sigh.

 

[maki2]

I had been wondering of anyone used a dehumidifier to reduce the moisture in their rigs. So many post warning against moisture build up and mold. I

Going on 4 years full time and I have had zero problems with mold. Of course I have been mostly in Arizona but I am in northern AZ in the mountains during the monsoon season. But it does not rain all day so I still have lots of fresh air exchange every day.

Sure sometimes I get some condensation on the inside of windows but a microfiber washcloth soaks it right up. Instead of wood center panels on my cabinet doors I have Phifertex mesh which lets the inside of my cabinets have some air movement and air exchange so I have no mold issues inside my storage areas. Air exchange is important, open windows or the doors at least once a day if possible long enough to get a decent change of air and you will be healthier and get rid of quite a lot of mold spores floating on that stagnant air as well as gaining extra fresh oxygen. It is just common sense stuff, do not turn your small dwelling space into a terrarium that is always closed up with the same damp moisture remaining inside it.

 

[Gr8ful]

I was in Rotary for many years. 2 guys in a club in BH, St Joe developed a water filter that would handle about 15 people or 2-3 families. It was simple stone, gravel, soil, sand just like ground wells work. We sent them all around the world & saved many children. They were concrete but changed to plastic. They had a 15 gal holding clean water tank. For $165 we could have them made, shipped (many by the military for free) & installed & the family's trained to use them. They had a 5 to 1 match & I paid for a bunch. The USDA was one of that matched. I wanted to buy one & promote to non Rotarions but they were never submitted one to the USDA for appoval even though they did a match. Amway & the plastic container maker ended up with the rights to them but I'll see what I can find. They were very simple, work extremlly well with over 99 pure water & 100% if 2 drops of bleach was added to the 15 gal holding tank. Here's a small article but I'll find more.
https://www.palisades-rotary.org/our-projects/biosand-water-filtersThis one is non Rotary by is close to how they work https://www.cleanindiajournal.com/what_is_bio_sand_filter/#:~:text=At the same time, the,difficult to be moved around.
https://grosche.ca/biosand-filters-...The filters have proven to,97-99% of bacteria https://www.usf.edu/nsf-ires/documents/mccannprojectsupplementary/bsf-booklet.pdf

 

[Gr8ful]

More links. I'm no expert but think they could likley be made a smaller dia to fit in a van.

https://www.purewaterfortheworld.org/2013/10/25/how-does-a-bio-sand-filter-work/
https://www.mlive.com/business/west-michigan/2012/04/how_grand_rapids_company_tripl.html
https://capdcalgary.org/water.html

 

[Tony's Dream]

If I found myself stranded in desert......dying of thrist......and absolutely no other options......then maybe. Otherwise......dump it.

 

[LargeMarge]

... cabinet doors I have Phifertex mesh... no mold issues inside my storage...Air exchange... spores floating on that stagnant air as well as gaining extra fresh oxygen.... do not turn your small dwelling space into a terrarium that is always closed [!].

.
a)
We heat with one Wave 3 catalytic heater... on propane.
"But but but LM!, propane burns into water-vapor so you will drown!"
.
True, oh so very true,  if our terrarium was sealed.
Staying a symbolic-yet-effective jump ahead of those spores, we always open two windows on opposite walls.
Escaping warm air carries humidity and odors.
.
b)
We avoid closed spaces such as cabinets and rooms behind doors.
Our interior is one yuge open box, a multi-purpose room engineered for simultaneous:
* cooking
* changing clothes
* reading and rithmatic
* sleeping
* wrasslin' with the dogs.
And gymnasties.
Our storage is milk-style crates, open on four sides and the bottom and top.
.
c)
Show of hands:
* how many think 'extra fresh' oxygen is better than regular oxygen?
Break into small groups, discuss.

 

[Happy Camper]

Show of hands:
* how many think 'extra fresh' oxygen is better than regular oxygen?
Break into small groups, discuss.

I prefer my oxygen with air. I have tried liquid oxygen, and while it works for my fish, it disagrees with me.

 

[TravelinTom]

Greetings.

Since most of us strive to be very conscious of our limited supplies of drinkable water, I'd like to know how feasible it is to collect gray water (from washing dishes or clothes, but only with a bio-degradeable soap such as Dr. Bronners) and run it through a gravity-fed water filtration system and back into a drinking water container.

• Would that water be safe to drink from a health and safety standpoint?
• Would that water taste clean?

Thanks!

How's your thoughts been on this post? Was just wondering (before reading ALL replies) if you considered using a reverse osmosis system. Yes, it too produces waste which maybe can be cycled thru again and again? Too much perpetual flow for a benefit? I think this is how the International Space station continues to have fresh water......